Apparatus for controlling reciprocatory movement of a gem stone across a polishing surface



Dec- 1, 1970 LEZIBOWI APPARATUS FOR TROLLING RE I ROCA'IORY MOVEMENT OF A GEM STONE ACROSS POLISHING SURFAGE Filed D60. 18, 1967 US. Cl. 51229 5 Claims ABSTRACT OF THE DISCLOSURE A gem stone polishing machine has a tang pivoted at its rear about a horizontal axis, means for reciprocating the tang lengthwise across a polishing surface and a system for accurately aligning the plane of reciprocation of the tang with the plane of the polishing surface in which a follower depends from the tang and is United States Patent 0 adapted to reciprocate over a guide surface whose inclination can be adjusted.

BACKGROUND OF THE INVENTION In certain industrial operations, it is necessary to reciprocate a component across a surface in a plane precisely parallel with the surface. 'For example, in diamond polishing it is common practice to reciprocate a diamond radially across the surface of a rotary wheel during polishing. If the diamond is not reciprocated precisely in the plane of the wheel surface, it may tend to bite into the wheel and damage the wheel surface.

SUMMARY OF THE INVENTION According to the invention, apparatus for controlling reciprocatory movements of a gem stone across a polishing surface comprises a tang having means at its forward end for mounting a gem stone at its forward end, a tang, supporting surface, means mounting the tang on the supporting surface for pivotal movement towards and away from the polishing surface and for reciprocatory movement whereby, gem mounted at the forward end of the tang can be reciprocated across the polishing surface, a dashpot assembly, and a follower member on the tang adapted to contact and reciprocate across the dashpot assembly when the tang is reciprocated to control the contact pressure between the gem stone and the polishing surface, the improvement comprising means being provided for adjusting the inclination of the dashpot assembly in the direction of reciprocation of the tang independently of the inclination of the supporting surface for controlling the plane of reciprocation of the gem stone.

The invention will now be described with reference to the accompanying drawing in which:

BRIEF DESCRIPTION OF THE DRAWINGS The sole figure is a diagrammatic side view of a diamond polishing machine.

DETAILED DESCRIPTION OF THE INVENTION In carrying the invention into effect according to one mode by way of an example, apparatus for polishing a diamond on a horizontal rotating wheel surface 1 comprises a generally horizontally extending tang 2 provided with a gem mounting chuck 3 at its forward end adapted to overlie the wheel, and the tang is mounted at its rear end on a horizontal fulcrum 4 so that the chuck can be pivoted towards and away from the wheel surface. The base of the fulcrum is mounted on a silding carm 3,543,450 1C6 Patented Dec. 1, 197

riage 5 so that the tang can be reciprocated lengthwise to move a gem mounted thereon across the wheel surface.

At a point intermediate the chuck and the fulcrum, the tang carries a depending follower 6, the lower end of which rests on the top surface of a dashpot plunger 7. The dashpot serving to cushion downward movement of the tang onto the wheel surface, and the top plunger surface also serves as a levelling guide for the tang with the dashpot creating a backpressure on the tang during polishing. The dashpot body is mounted on a horizontal fulcrum 8 parallel with the tang fulcrum 4 so that the inclination of the plunger surface can be adjusted in the direction of the lengthwise reciprocation of the tang. The dashpot can be fixed at the required inclination by a pair of adjusting screws 9 acting on opposite sides of a plate 10 attached to the dashpot body.

In operation, it is possible to hear if a stone is not being reciprocated across the wheel surface in precisely the correct plane, with a squeaking sound being emitted. To rectify this, it is merely necessary to manually adjust the inclination of the dashpot by trial and error until the squeaking is eliminated. The dual fulcrum system enables reciprocation in the precise plane of the wheel surface to be achieved.

1 claim:

1. An apparatus for controlling the reciprocatory movements of a gem stone across a polishing surface, comprising a tang, means at the forward end of the tang for mounting a gem stone, a tang supporting surface, means mounting the tang on the supporting surface for pivotal movement towards and away from the polishing surface and for reciprocatory movement whereby a gem stone mounted at the forward end of the tang can be reciprocated across the polishing surface, a dashpot assembly, and a follower member on the tang adapted to contact and reciprocate across the dashpot assembly when the tang is reciprocated for controlling the contact pressure between the gem stone and the polishing surface, the improvement including means being provided for adjusting the inclination of the dashpot assembly in the direction of reciprocation of the tang independently of the inclination of the supporting surface for controlling the plane of reciprocation of the gem stone.

2. The apparatus as claimed in claim 1 in which said tang is mounted on said supporting surface for lengthwise reciprocation.

3. The apparatus as claimed in claim 1 in which the dashpot assembly is defined by a liquid dashpot and the follower member is adapted to contact and reciprocate across the plunger of the dashpot.

4. The apparatus as claimed in claim 1 in which the dashpot assembly is mounted for adjustment of its inclination about a substantially horizontal fulcrum.

5. The apparatus as claimed in claim 4 in which said dashpot assembly is mounted on a plate and manually adjustable screws are provided above and below the plate for adjusting the inclination of the assembly.

References Cited UNITED STATES PATENTS 2,569,592 10/1951 West 5l-229 FOREIGN PATENTS 559,628 10/1957 Belgium.

HAROLD D. WHITEHEAD, Primary Examiner US. Cl. X.R. 5l-122 Dedication 3,543,450.-Ale0 Leibowitz, London, England, APPARATUS FOR CON- TROLLING RECIPROOATORY MOVEMENT OF A GEM G SURFACE. Patent dated Dec. 1,

STONE ACROSS A POLISHIN 1970. Dedication filed Sept. 7, 1973, by the assignee, Spectrum Diamonds (Proprietary) Limited. Hereby dedicates the entire remaining term of said patent to the Public.

[Oflicial Gazette December 935, 1973.] 

